Magnetic Resonance Imaging(MRI) has become the gold standard of evaluation of lumbar spinal stenosis (LSS. LSS is defined as the narrowing of the spinal canal. Thus far, there has been no formal grading system in literature. Physicians, particularly radiologists, in their interpretations, currently describe the degree of stenosis at each level as normal, mild, moderate or severe. Unfortunately, there is no consensus on criteria of these definitions. Treatments and surgical plans are based primarily on this information. Consequently, the reliability and accuracy of this information is critical in terms of optimizing outcomes.